Width Of Cut Research Articles

A computational model for thick concrete slab demolition using soundless chemical demolition agent

Soundless chemical demolition agents (SCDAs) provide a feasible route to meet the demolition in the modern construction industry. Exploration of how to efficiently demolish reinforced concretemembers with SCDAs is in deep demand. To investigate the method and computational model of demolishing thick concrete slab, static crushing experiments of 12 thick concrete slab specimens with different parameters were carried out. To remove the constraint of reinforcements, the reinforcements in the upper part of the thick concrete slab specimens were cut off along the hole connection and its extension line before grouting. The results showed that cracks were formed at the cutting seams on the upper surface due to the defect caused by cutting reinforcements, and these cracks extended to the bottom of the specimens. The development of cut seam width was over 80% on the first day, and 20% in the following day. Besides, the ratio of the area of the cut seams on the upper surface of the specimen to the area of the upper surface of the specimen (i.e. crack area ratio) was proposed to evaluate the influence of the compressive strength of concrete, hole spacing, and hole diameter in the concrete demolition. Finally, a new computational model for calculating hole spacing by taking time, compressive strength of concrete, hole diameter, ambient temperature, and crack area ratio into consideration was proposed. The proposed computational model was verified with experimental data and was expected to guide the application of SCDAs in civil engineering.

Impact of Road Cuts in Slope Stability in Hilly Regions of Nepal

This paper reviews the geological and engineering aspects of rural road construction in the hilly areas of Nepal. The general background in geological, climatic and geographical setting is briefly presented in reference to the five-zone Himalayan model for the Nepal Himalayas. Then, alignment selection of rural roads is discussed in the context of the five zone mountain model. The impact of road cross section design and construction on mountain slopes has been studied. The cut width is a key geometric design parameter that has a significant impact on slope stability and volume of excavation. The choice of cut width in cross-section is reviewed and appropriate cut width in cross-section is recommended in terrain slopes to minimize slope failures and volume of excavation.

Anthropometric measurements of patellar ridge using computed tomography-based three-dimensional computer models

BackgroundThe objectives of this study were to investigate the anatomic morphology of patellar ridge using computed tomography-based three-dimensional (3D) computer models and to assess the center of the patellar ridge after virtual resections.MethodsWe selected 80 patients, 40 males (age, 33.2±6.8 years) and 40 females (age, 30.6±7.2 years), who were slightly symptomatic with soft tissue injury of the knee joint. The right or left knees were scanned by computed tomography (CT). The CT data of 160 knees was used to construct 3D computer models by image analysis software (Mimics). Variables such as the angle between the patellar ridge and patellar long axis, the distance between the center of the patellar ridge and the center of patellar cut after virtual resections were measured. We detect differences between the sides and genders with the 3D computer models by Student’s t test. Simple linear regression and correlation test was used to correlate the patellar ridge center to the center of the patellar cut.ResultsAccording to the available data, there were significant gender differences in the length and width of patellar cut after virtual resections even with strict control for the height and weight of the patients. The angle between the patellar ridge and the patellar long axis was 11.24° ± 3.62°. The angle in male patients was 10.17° ± 4.82°, and it was 12.28°± 3.78° in female patients. The morphological difference was statistically significant (P < 0.05). After using the subchondral method to virtually resect the patellae, with reference to the center of the patellar cut, the center of the patellar ridge lies superiorly and medially in 88.75%, inferiorly and medially in 8.75%, laterally and superiorly in 2.5%, and in no case laterally and inferiorly. The intra-observer reliability regarding the dimensional measurements was excellent in this study.ConclusionsAdvances in 3D computer models had resulted in the availability of preoperative measurement and virtual planning. The anthropometric dimensions of this study could provide general information for guiding surgical management of the patella in total knee arthroplasty (TKA) and were useful in designing patellar implants.Clinical relevanceThe placement of the patellar component during TKA differs from one patella to another. The anatomic morphology information of the patellar ridge is helpful for surgeons to perform patellar resurfacing in TKA.

Bony landmarks, distances and their correlations to each other, which can be used during periacetabular osteotomy: a CT study performed on dysplastic hips.

As a surgical technique for hip dysplasia, Bernese periacetabular osteotomy (PAO) still poses technical difficulties and unclear surgical steps like the depth of the first ‘ischial’ cut, the start of the iliac cut and the width of the retroacetabular cut to prevent either iatrogenic joint entrance or posterior column fracture. Twenty-seven dysplastic hips (CE < 25°) were randomly matched with nondysplastic hips (n: 27, CE > 25°). 3D CT sections of the hips were evaluated and the width of the ischium, the distance from the infra-acetabular groove to the ischial spine, from the anterior superior iliac spine (ASIS) to the joint or sciatic notch or the sciatic spine, from the most medial point at the acetabulum to the posterior column, ischial spine or sciatic notch were measured for each group and correlated. The distances (mm) from the infra-acetabular groove to the ischial spine (42 ± 4, 44 ± 4, P: 0.03), the anterior superior iliac spine to the joint (52 ± 6, 60 ± 3, P: 0.03), the most medial point at the acetabulum to the posterior column (34 ± 2, 36 ± 2, P: 0.005) were shorter in the dysplastic group. The distance from the ASIS to the sciatic notch was correlated with the distance from the infra-acetabular groove to the ischial spine, from the ASIS to the joint and the most medial point at the acetabulum to the posterior column. The distance from the ASIS to the sciatic notch can be used intraoperatively to guess the X-ray guided or blindly osteotomized stages to predict the width or depth of the osteotomy to prevent intraarticular extension or posterior column fracture.

Reliability of the Cutting Alignment Scoring Tool (CAST) to Assess Trunk and Limb Alignment During a 45-Degree Side-Step Cut.

BackgroundThree-dimensional (3D) motion analysis is considered the gold standard for evaluating human movement. However, its clinical utility is limited due to cost, operating expertise, and lengthy data processing time. Numerous qualitative scoring systems have been introduced to assess trunk and lower extremity biomechanics during functional tasks. However, the reliability of qualitative scoring systems to evaluate cutting movements is understudied. Purpose/Hypotheses: To assess the inter-rater and intra-rater reliability of the Cutting Alignment Scoring Tool (CAST) among sports medicine providers and to evaluate rater agreement of each component of the CAST. The hypotheses were: 1) there would be good–to-excellent inter-rater and intra-rater reliability among sports medicine providers, 2) there would be good to almost perfect agreement for cut width and trunk lean variables and moderate to good agreement for valgus variables of the CAST.Study DesignRepeated MeasuresMethodsTen videos of a 45-degree side-step cut performed by adolescent athletes were independently rated on two occasions by six raters (2 medical doctors, 2 physical therapists, and 2 athletic trainers). The variables assessed include trunk lean to the opposite direction of the cut, increased cut width, knee valgus at initial load acceptance (static), and knee valgus throughout the task (dynamic). Variables were scored as either present, which were given a score of “1”, or not present, which were given a score of “0”. Video sequence was randomized in each rating session, and a two-week wash out period was given.ResultsThe cumulative inter-rater and intra-rater reliabilities were good (ICC: 0.808 and ICC: 0.753). Almost perfect kappa coefficients were recorded for cut width (k=0.949). Moderate kappa coefficients were found for trunk lean (k= 0.632) and fair kappa coefficients were noted for dynamic and static valgus (k=0.462 and k= 0.533 respectively).ConclusionThese findings suggest that the CAST is a reliable tool to evaluate trunk and LE alignment during a cutting task by sports medicine providers.Level of EvidenceLevel 2 Diagnosis

Machining simulation of Ti6Al4V using coupled Eulerian-Lagrangian approach and a constitutive model considering the state of stress

The accuracy of a machining model depends on the capability of this model to describe the physical phenomena associated to the real machining system. This includes the material constitutive model and the approach used to describe the field flow of the material in cutting. In this paper, a model of high speed machining (HSM) of Ti6Al4V titanium alloy is developed. This cutting model includes the proposed constitutive model considering the influence of strain hardening, strain-rate, temperature, and state of stress (e.g., stress triaxiality and Lode parameter) in the material plasticity and damage. Finite Element Method (FEM) using Coupled Eulerian-Lagrangian (CEL) approach is used to simulate the cutting model. A sensitivity analysis of the influence of the mesh topography on the chip geometry and cutting force is performed resulting in the determination of the optimal element size and element orientation. Simulation results obtained using the CEL approach are compared with those obtained using the Lagrangian one. Moreover, simulated cutting force and chip geometry obtained using the proposed constitutive model are compared with those obtained using the Johnson-Cook (J-C) model, and experimental data. Both chip geometry and cutting force predicted by the proposed constitutive model is closer to the experimental one than the J-C constitutive model. The CEL approach combined with the proposed constitutive model can simulate material side flow, which results in a larger width of chip compared to the width of cut, and in the formation of lateral burr on the workpiece. It also permits simulating the cyclic variation of the plastic strain and topography of the machined surface along the cutting direction, observed experimentally.

Stability analysis of thin-walled parts end milling considering cutting depth regeneration effect

Weak rigid parts are widely used in aerospace industry. These parts are characterized by thin walls. Most of these parts have the meter-level size and mesh surface, thus have a requirement for tool accessibility. Therefore, the end milling is an applicable process to reduce the thickness of these parts. Due to the weak rigidity of these parts in the normal direction, severe chatter will occur in the machining process, which will reduce the machining efficiency and spoil the machining surface, so the processing stability of the thin-walled part needs to be studied. In this paper, the dynamic model for end milling of thin-walled parts is presented. The regeneration effect in the surface normal direction is proposed, and the dynamic equation is constructed considering the vibration of the workpiece in the cutting tool axial direction. The stability lobe diagram is obtained by numerical method. It is found that the stability of weak rigid parts end milling is related to the cutting speed, the feed rate, and the width of cut, but not to the cutting axial depth. Finally, cutting experiments are conducted. The experimental result is coincident well with the prediction, thus verifying the proposed dynamic model and the stability analysis method.

Simulation and Optimization of Machining Time During Milling AISI P20 Steel

This paper presents a simulation and optimization of machining time during milling of AISI P20 steel using the Taguchi method. The simulation was conducted using the L9 orthogonal array on a Swansoft CNC Simulation with the Fanuc OiM operating system. Milling simulations provide faster time and lower cost of getting machining time data compared to experiments on actual machines. The cutting tool uses a 12mm flat endmill and 4 number of flutes. Machining simulation parameters on surface finishing are speed, feed rate, and width of cut (WoC), while the depth of cut remains. NC programs, according to zigzag, paralel spiral, and constant overlap spiral toolpath strategies. The parameters of speed and feed rate have been calculated based on WoC values (5%, 10%, and 20%) of the AISI P20 steel material. The lowest machining time from each toolpath strategy is generated from WoC 20%, 3032 RPM speed, and 2286 mm min−1 feed rate. Setting these parameters on the three toolpaths simulated gets the lowest machining time. The toolpath strategies that provide the lowest machining time are the constant overlap spiral namely 1.62 min or 1 min 37 seconds. ANOVA analysis on various toolpaths found that the WoC and feed rate were significant factors (P less than 5%) affecting machining time, while the speed factor exceeded P probability (5%). The calculation of the S/N Ratio on various toolpath strategies shows that the width of cut is ranked 1, feed rate as ranked 2, and speed is ranked 3 affected the machining time.

Analysis of neodymium-doped yttrium-aluminum-garnet laser and experimental prospects for cutting micro-thin black walnut veneers in industry

By structurally and practically analyzing the use of Nd: YAG laser for cutting black walnut veneer, this study considered practical and environmental concerns regarding the global warming protection measures. A numerical model of laser wood veneer cutting was based on the relation between process parameters and the material thickness. A pulsed Nd: YAG was used to cut black walnut veneer of 0.3 mm thickness under different machining conditions regarding laser power and cutting speed to study the cut kerf width. An analysis of variance was conducted to test the significance of machining parameters. The parameters studied were laser power, cutting speed, kerf width, cut surface, safety, and eco-friendliness. The results showed that the kerf width decreased significantly with increased cut speed and, inversely, by laser output power. An efficient cut with a narrow kerf, clean and smooth, with less burn, was possible at laser cutting speeds of 2.5, 5.0, and 5.5 mm/s with kerf widths of 0.544, 0.69, 0.62 mm, respectively. As multiple factors affect the micro-thin wood laser cutting process, finding the optimal process parameters is crucial for successful machining with no burn effect.

Experimental Investigation and Multi-Response Optimization of Machinability of AA5005H34 Using Composite Desirability Coupled with PCA

Minimum quantity lubricant (MQL) is an advanced technique in machining to achieve sustainability, productivity, higher precision, economic benefits, and a reduction in carbon footprints. The present research work aims to investigate the effect of the cutting process parameters of the end milling of AA5005H34 material under dry and MQL cutting environments. The key performance indicators of machining include the surface roughness profile, the material removal rate, and tool wear. Surface roughness parameters are measured with the help of the Mitutoyo surface roughness tester, and the cutting tool wear is measured according to the ISO 8688-2:1989 standard using a scanning electron microscope (SEM). Sixteen experiments are designed based on the Taguchi orthogonal array mixture design. Single responses are optimized based on signal to noise ratios, while for multi-response optimization composite desirability function coupled with principal component analysis is applied. Analysis of variance (ANOVA) results revealed that the feed rate followed by spindle speed, axial depth of the cut, width of the cut, and cutting environment are the most significant factors contributing to the surface roughness profile, material removal rate, and tool wear. The optimized parameters are obtained as cutting speed of 3000 rev/min, feed rate of 350 mm/min, axial depth of cut of 2 mm, and width of cut of 6 mm under an MQL environment.

A Study of Fiber Laser Micro-Grooving of 316L Stainless Steel at Different Temperatures

The present article deals with the generation of micro-grooves on 316L stainless steel (SS) by a nanosecond pulsed fiber laser system. Fabrication of micro-grooves on 316L SS has immensely contributed to the biomedical and automotive industries through improving the mechanical, lubrication, and corrosion resistance properties. In the present work, the considered process parameters are the preheating temperature (100°C and 200°C), along with the room temperature (24°C), cutting speed, sawing angle, pulse frequency, and laser power. The ranges of cutting speed and sawing angle are 0.1–1.1 mm s−1 and 0.1°–1°, respectively. Besides, pulse frequency and laser power vary from 55 kHz to 85 kHz and from 15 W to 45 W, respectively. The constant parameters are the pulse width of 99% and assist air pressure of 6 kgf cm−2. The variable parameters for the analysis are cut width and heat-affected zone (HAZ) width. The article aims to showcase a comprehensive study of fiber laser process parameters at different temperatures (preheated condition and room temperature) with variable sawing angles to produce better process control and bring about each considered process parameter’s critical value. The experimental results show that higher dimensions of cut width and HAZ width are observed at 200°C with the increment of sawing angle and laser power, compared to other temperatures. With the increment of cutting speed and laser power, the HAZ width tends to rise sharply. A significant drop in cut width and HAZ width dimensions is observed with the increment in pulse frequency for any temperature.

Quantitative determination of cut efficiency during soft tissue surgery using diode lasers in the wavelength range between 400 and 1500\xa0nm

Within the scope of this ex vivo study, the cut efficiency was investigated with eight diode laser wavelengths in the range from 400 to 1500 nm. Incisions on porcine gingiva samples were generated in CW-mode at a power range of 0.5–4 W using a bare fiber (∅ = 320 μm) in contact and non-contact mode at a cut speed of 2 mm/s. Cut depths, cut widths, and thermal damages were recorded based on histological sections and were evaluated via measurement masks. Moreover, with respect to the controllability of a therapeutic measure, an efficiency factor was defined. At powers above 2 W, for 445 nm, the maximum cut depth was 820 μm and 344 μm for 810 nm, respectively. At all wavelength and power ranges, the cut width averaged 125 μm. At minimum output power (0.5 W), the spatial expansion of the thermal damage in the tissue surface layer corresponds in the blue/green wavelength range from the very beginning of the laser impact to the fiber core diameter. It could be shown that increases in the diode laser power output do not correlate to the same extent with the incision depth nor with thermal damage to tissue.

Effect of the width of cut tobacco on the quality of slim cigarette

In order to further explore the characteristics of slim cigarette processing technology, this study designed different cut width (0.7mm and 0.8mm) of product A, and carried out the experiments of making and rolling under the same process conditions, and evaluated the influence of the width of cut tobacco on the quality of slim cigarette. The results showed that: the 0.7mm cut width has the following advantages: Processing characteristics, Short rejection rate, Reducing draw resistance, Weight stability, Uniformity of density is better than 0.8 mm cut width, and 0.7 mm cut width is more suitable for the production of slim cigarette.

Simulation of material side flow using a 3D coupled Eulerian-Lagrangian approach and a constitutive model considering the stress state

New advance in modelling of the machining process is of great significance to improve component performance and manufacturing efficiency. This includes the material constitutive model and the approach used to describe the field flow of the material in cutting. In this study, a 3D model of high speed machining (HSM) of Ti6Al4V titanium alloy is developed. The coupled Eulerian-Lagrangian (CEL) approach was used to simulate the proposed cutting model. This cutting model includes a proposed constitutive model considering the strain hardening, strain-rate, temperature and stress state (e.g., stress triaxiality and Lode parameter) in the material plasticity and damage. This machining model is able to simulate the phenomenon of material side flow, which results in a larger chip width when compared to the width of cut and the lateral burr formation. The phenomenon of material side flow is validated by experimental results. The distribution of plastic strain and stress state shows that the workpiece transforms from plane strain state in middle surface to plane stress state in lateral surface, which finally results in the formation of lateral burr.

Rational parameters of the transportless technological scheme for the development of strata with maximum permissible dip angle

In this article the rational value of overburden cut width and thickness of transportless overburden at mining of two dispersed flat seams IV-V and VI at Kureinsky section of Sibirginsky open pit mine are presented, which makes it possible to minimize the volume of rock re-excavation under the condition of the planned annual productivity of coal on the open pit and to ensure reduction of stripping costs. This task is complicated by the fact that the dip angle at the section is close to the limit on the condition of the possibility of spoiling of internal dump, and since the overburden rocks of the section are represented mainly by large-block sandstones on the clay cement and siltstones and their compressive strength is 60-80 MPa, then it is required to use a drilling and blasting method of their preparation for excavation. Under such conditions, optimizing the parameters of the transportless excavation scheme is of special importance for effective mining of the section.

Multi-Criteria Optimization of Aerospace Alloys in WEDM Using TOPSIS

Wire EDM is commonly used for machining of complex profiles in hard and exotic materials. In the present work the key performance of Wire EDM such as wire cutting speed, surface roughness and cut width in machining of three different aerospace class materials such as near beta titanium alloy, forged nickel base alloy and aged aluminum alloy are studied. Apart from electrical parameters, the wire with zinc coated brass and plain brass are used. TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) is the Multi-Criteria Decision-Making method used for selecting the best setting of control parameters. Parameter sets are ranked from best to worst based on the performance score. Zinc coated wire outperforms the brass wire almost for every response variable in case of Ni and Ti alloy while with Al it is as good as plain wire.

Draught Requirements of Tillage Tines in Clay Soil under Indoor Soil Bin Conditions

Large tine (Tl) and sweep tine (Tw) were the different model tillage tines used for this research. The blades were used on clay soil in a soil bin of dimension 9.0 × 0.85 × 0.5m located in the Department of Agricultural Engineering of the Federal University of Technology, Akure, Nigeria. The clay soil used for the experiment was obtained from Agricultural Engineering Step B Farm. The objective of this study was to evaluate the draught requirements of the model tillage tools and to evaluate and model the parameters of the soil profile produced under different operating conditions. It involved testing and evaluation of tool shape, depth (12.5 -100mm) and rake angles (300, 450, and 900) and forward speed (0.17m/sec) on draught force. Soil profile patterns measured by a profilometer was analyzed using the following parameters – maximum Width of soil cut (Wfs), Ridge-to- Ridge Distance (RRD), furrow depth (df), height of ridge (Hr), maximum Width of Soil Throw (TDW) and tool width (w). Results showed that draught is directly proportional to the depth of the tine at a certain rake angle. The Tw had the least draught while Tl had the highest draught. Analysis of soil disturbance parameters revealed an increase in parameters with increasing cone index and depth of the tines. The study provides relevant data in the design of soil engaging tools and sustainable crop production. Keywords: Draught, Clay, Soil disturbance, Tillage, Tines.

Draught Requirements of Tillage Tines in Clay Soil under Indoor Soil Bin Conditions

Large tine (Tl) and sweep tine (Tw) were the different model tillage tines used for this research. The blades were used on clay soil in a soil bin of dimension 9.0 × 0.85 × 0.5m located in the Department of Agricultural Engineering of the Federal University of Technology, Akure, Nigeria. The clay soil used for the experiment was obtained from Agricultural Engineering Step B Farm. The objective of this study was to evaluate the draught requirements of the model tillage tools and to evaluate and model the parameters of the soil profile produced under different operating conditions. It involved testing and evaluation of tool shape, depth (12.5 -100mm) and rake angles (300, 450, and 900) and forward speed (0.17m/sec) on draught force. Soil profile patterns measured by a profilometer was analyzed using the following parameters – maximum Width of soil cut (Wfs), Ridge-to- Ridge Distance (RRD), furrow depth (df), height of ridge (Hr), maximum Width of Soil Throw (TDW) and tool width (w). Results showed that draught is directly proportional to the depth of the tine at a certain rake angle. The Tw had the least draught while Tl had the highest draught. Analysis of soil disturbance parameters revealed an increase in parameters with increasing cone index and depth of the tines. The study provides relevant data in the design of soil engaging tools and sustainable crop production. Keywords: Draught, Clay, Soil disturbance, Tillage, Tines.

К ВОПРОСУ ПОДГОТОВКИ РЕЖУЩЕГО ИНСТРУМЕНТА ПРИ РАСПИЛОВКЕ ЛЕСОМАТЕРИАЛОВ НА ЛЕНТОЧНОПИЛЬНОМ ОБОРУДОВАНИИ

the main drawback of circular sawing machines is the presence of broken teeth in the cut. In case of vibrations, violation of the saw plane, mismatch of the feed direction with the saw planes, and rebasing, these teeth spoil the processing surface. Belt sawing allows you to ensure high quality of lumber on the roughness of their surface at high feed rates; increase productivity by 1.5-2 times due to mechanization and automation of technological operations. One of the most important advantages of band saws is the small width of the cut, which is 1.5-2 times smaller than that of the sawmill; the small thickness of the saw ensures low consumption of wood in sawdust and high volume output of lumber. Sawing wood on band saws, in the vast majority of cases, is characterized by face cutting. Of the 3 forms of chip formation when cutting into the end, for band saws, the most characteristic is the formation of the chip element by chipping it with the stratification of wood along the bottom of the cut. The quality of the surface, in terms of its roughness, in addition to the formation of the chip element, is affected by its location in the interdental space, the presence and degree of compression and transportation of the chip element. The quality of the surface, in terms of its roughness, in addition to the formation of the chip element, is affected by its location in the interdental space, the presence and degree of compression and transportation of the chip element. As a result of studies of the initial conditions for the development of the teeth sharpening scheme, the orientation of the active elements of the blade relative to the middle plane of the saw can be identified as the main ones.

Mechanical and electrolytic hybrid grinding of metal ceramic composites using coarse diamond grinding wheel

The application and development of metal ceramic composites have been restricting due to its low grinding efficiency and ground quality. In this paper, the hybrid machining technology combined mechanical with electrolytic grinding based on dressed coarse diamond grinding wheel is proposed to perform efficient and precise grinding of metal ceramic composites. First, the dry electrical discharge dressing technology was used to dress coarse diamond grinding wheel to obtain high grain protrusion and sharp micro-grain cutting edges. Next, the mechanical and electrolytic hybrid grinding process using dressed coarse diamond wheel was developed to grind metal ceramic. Finally, the effects of different process parameters on ground surface topographies and surface roughness were investigated. It is shown that the proposed hybrid grinding method was feasible and can effectively improve the ground surface quality. The experimental results show that the optimal process parameters including the depth of cut, open-circuit voltage and impulse width were 5 μm, 20 V and 400 ns, respectively. Compared with traditional mechanical grinding, the ground surface roughness by the proposed hybrid machining method was improved by about 25%.